Gas furnace construction



Aprll 28, 1959 H. A. MARBLE ET AL GAS' FURNACE CONSTRUCTION Filed NOV. 14, 1955' "2 Sheets-Sheet 1 INVENTOR-S' HAROZD A. MARBL! ByCf/[SH'R P. BURBEY April 28, 1959 Filed Nov. 14, 1955 H. MARBLE ET AL GAS FURNACE CONSTRUCTION I IIIIIIIIJII'IIIIIIIIIII, rllllllllllllllli 2 Sheets-Sheet 2 nited States atent 2,884,048 i atented Apr. 28, 1959 GAS FURNACE CONSTRUCTION Harold Arthur Marble, Bnrlingamc, and Chester P. Burbey, San Francisco, Calif., assignors to International Sales Company, San Francisco, Calif., a corporation of California Application November 14, 1955, Serial No. 546,474

1 Claim. (Cl. 158-7) This invention relates generally to the construction of gas furnaces and more particularly to the construction of gas furnaces suitable for use within relatively confined spaces in homes, apartments and the like.

It is well known that the recirculation of burned gases occurs in the closed type of combustion chambers used in many conventional gas furnaces. This recirculation of burned gases often causes incomplete combustion which results in the production of carbon monoxide and a drop in the efliciency of the combustion chamber. Many gas furnaces utilized in homes, apartments and the like are provided with reduced combustion areas or chambers in order that the furnaces may be placed in relatively small spaces. Since these furnaces have reduced combustion areas, the effect of recirculation is much greater and many of the gases including carbon monoxide spill out of the burner opening. This is particularly undesirable because it may effect the health of the people even though the concentration of carbon monoxide may not be suflicient to cause death.

In general, it is an object of the present invention to provide an improved gas furnace construction which reduces to a minimum the spillage of gases out of the burner opening.

Another object of the invention is to provide an improved gas furnace construction of the above character in which novel means are provided in the combustion chamber to inhibit the spillage of gases out of the burner opening.

Another object of the invention is to provide a gas furnace construction of the above character in which a baffle and separate duct or channel are provided within the combustion chamber to lead off any gases which would normally spill out of the furnace opening.

A further object of the invention is to provide an improved gas furnace construction of the above character which is relatively small and compact and has a B.t.u. rating substantially greater than that of a conventional furnace of the same size.

Additional objects and features of the invention will appear from the following description in which the preferred embodiment has been set forth in detail in the accompanying drawing:

Referring to the drawing:

Figure 1 is a side elevational view with certain parts of the housing cut away showing a gas furnace construction incorporating our present invention.

Figure 2 is a front elevational view of the gas furnace shown in Figure 1 with certain parts of the housing cut away and with the front cover removed.

Figure 3 is a cross sectional view taken along the line 33 of Figure 1.

Figure 4 is a cross sectional view taken along the line 44 of Figure 2.

Figure 5 is an enlarged cross sectional view taken along the line 55 of Figure 3.

In general, the present invention consists of providing a special baflle mounted within the combustion chamber to collect recirculating burned gases and a duct or channel to lead off the gases collected to prevent the recirculating burned gases from spilling out of the burner opening.

The embodiment of our invention shown in the ,drawing consists of a substantially rectangular housing 11 in which are mount-ed a blower assembly 12, a pair of combustion and heat transfer units 13 and 14 and a burner assembly 16. The housing 11 is fabricated of any suitable material such as sheet metal to provide side walls 17 and 18, rear and front walls 19 and 21 and bottom and top walls 22 and 23.

The blower assembly 12 consists of a blower housing 24 which is fixed to a plate-like member 26. The platelike member 26 is shock mounted on a pair of angular supports 27 fixed to the side walls 17 and 18. A fan or blower 28 is journalled within the blower housing 24 and is driven by a motor 29 fixed to the plate-like member 26. The blower serves to draw air through a grille 32 mounted in the front wall of the housing and into openings 33 in the sides of blower housing to discharge the air through an opening (not shown) in the plate-like member 26 into the upper portion of the housing 11. 4

The combustion and heat transfer units 13 and 14 are fixed to a vertical face plate 36 which has its bottom end fastened to the plate-like member 26 at 37 and which has its upper portion connected to the top wall of the housing at 38. The combustion chambers 13 and 14 are shown particularly in Figures 3, 4 and 5 and consist generally of two pieces 41 of sheet metal with each sheet being formed, as by a pressing operation, to provide portions 41a through 41e inclusive. The bottom, top, rear and front edges of the pieces 41 are connected together by suitable means as by seam or spot welding to form a unitary assembly with a burner opening 42 and a discharge orifice 43 which extend through openings in the face plate 36. The portions 41a are curved to provide a space 44 for receiving a portion of the burner assembly 16. The portions 41b are spaced apart and substantially parallel to provide a combustion area 46. Portions 410 are inclined and form a passage leading to a space 47 defined by portions 41d which are also spaced apart and substantially parallel. Portions 412 are substantially semi-circular in cross section and form a discharge passage 48 connected to the discharge orifice 43.

The burner assembly 15 consists of a pair of burners 5'1 and 52 which are connected by piping 53 to suitable control devices 54, 56 and 57 well known to those skilled in the art of gas furnace building. Control device 57 is connected to a suitable source of gas supply 58. The entire burner assembly 12 is supported by a bracket 59 fixed to the piping 53 and the face plate 36.

An elongated duct or channel 61 is mounted adjacent the rear side of the face plate 36 and has its lower extremity 62 extending through a lip 63 in the combustion chamber adjacent the burner opening 42. The upper extremity 64 extends through an opening 66 in the face plate 36. The duct or channel 61 is formed of a substantially U-shaped member 67 which has its side edges secured to a flat plate 68 to form a substantially rectangular duct or channel. It will be noted that the upper extremity 64 is slightly flared to facilitate exit of the gases from the channel 61.

The discharge orifice 43 and the channel 61 both discharge into a draft hood 69 which is connected to a venting pipe 71. A grille 72 in the front wall 21 serves to permit air to flow into the lower open end of the draft hood 69.

A substantially L-shaped bafile 74 is mounted adjacent the burner opening and its lower end 76 extends through the burner opening and is connected to the face plate 36 by suitable means such as screws 77. The upper end 78 of the bafile extends into the interior of the combustion chamber near the front portion thereof for a purpose hereinafter described.

The upper portions of the rear and side walls may be provided with suitable insulation 81. A hot air duct 82 is connected to an opening 83 in the top wall. A plurality of baflles 84 are mounted on the side and one of the wall portions 410 and serve to deflect the air passing upwardly from the blower 28 into a region adjacent the side walls of the combustion chambers 13 and 14.

Operation of our gas furnace may now be described as follows:

Let it be assumed that the burners 51 and 52 are operating and that combustion is taking place in the combustion and heat transfer units 13 and 14. Fresh air is drawn through the grille 72 into each of the burner openings 42 to support combustion within the combustion and heat transfer units. The hot burned gases from the burners rise in the units 13 and 14 as shown by the arrows within the units and pass into the discharge passages 48 and out the discharge orifices 43 into the draft hood 69. However, as indicated by the smaller arrows, recirculation of some of the hot burned gases occurs in closed combustion and heat transfer units of this type and move in a more or less clockwise direction as viewed in Figures 2 and 4.

As previously explained, the effect of recirculating burned gases is to partially smother the flames from the burners causing incomplete combustion with the resulting production of carbon monoxide and a drop in the efficiency of the burner. In addition, some of the recirculating gases often escape through the burner opening 42.

In our burner construction, the baflle 74 collects a substantial portion of the recirculating gases after which they are passed off through the duct or channel 61 into the draft hood 69. In this manner, the gases which would normally tend to spill out of the burner opening 42 are passed up through the channel 61 and discharged into the draft hood 69 and carried off through the venting pipe 71.

It has also been found that by utilizing a gas furnace construction of this type, the B.t.u. rating may be in- 4 creased approximately ten percent without increasing the size of the combustion chambers and the housing of the gas furnace. This is particularly advantageous since home builders and apartment builders wish to be supplied with a furnace of the smallest size having the desired B.t.u. rating.

It is apparent from the foregoing that we have provided a gas furnace construction which is particularly adaptable for use within homes, apartments and the like. By preventing the escape of noxious gases into the home, a health hazard is eliminated while at the same time making it possible to increase the B.t.u. output of the furnace.

We claim:

In a gas furnace construction, a housing, a face plate mounted in said housing, walls forming substantially closed combustion and heat transfer unit mounted on said face plate and having a burner opening in the lower portion of the same and a discharge opening in the upper portion of the same, a burner mounted in said burner opening, venting means, said discharge opening being in communication with said venting means, a vertical duct mounted on said face plate adjacent the rear side thereof, said duct having its lower end disposed in the lower portion of said combustion and heat transfer unit and having its upper end emptying into said venting means, and an L-shaped baffle mounted in said combustion chamber and having its upper end directed upwardly in said combustion chamber in the front portion thereof and having its lower end extending through said burner opening adjacent the lower end of said duct, the lower end of said bafile being connected to the face plate adjacent the upper side of said burner opening, said bafile serving to collect recirculating burned gases and lead them to the lower end of said duct whereby said recirculating burned gases pass through said duct into said venting means.

References Cited in the file of this patent UNITED STATES PATENTS 52,033 Conner Ian. 16, 1866 109,749 Morse Nov. 20, 1870 289,840 Ingling Dec. 11, 1883 1,950,213 Barnett et al Mar. 6, 1934 2,658,504 Jaye et a1 Nov. 10, 1953 at-"e 

